Dayjo.org offers a couple of free music pieces that are very cool for scenes where you need just some ambient music, nothing too dramatic or suspenseful.

And finally, my personal favourite:Incompetech offers a massive collection of music free to listen to and download. You can search for music to create a certain mood or you can just take a look at the different collections of film scores (scroll right down to the bottom). There's also a lot of other music there, from folk to electronica.

So if you'll excuse me, I'm off to browse Incompetech. I need to get my stuff together for the start of my Endland campaign in four weeks.